Acids and Bases/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby. An animation shows a robot, Moby, standing at a table. There is a pitcher on the table and three lemons. Moby is holding a fourth lemon. He squeezes it. Some of the juice falls into the pitcher, while some of the juice sprays out the other side of the lemon. This juice goes off screen to the right. TIM: Ow! That stings! The scene changes to show a man, Tim. He has yellow lemon juice all over his face as he covers it up with one hand. He then reads from a letter. TIM: Dear Tim & Moby, we're learning about pH and I need to know how acids and bases are different. From, Chelsea. The scene changes to Tim and Moby as Tim wipes the lemon juice of his face. TIM: Well, lemon juice is certainly an acid. It tastes sour, and it stings if it gets in your eye or a cut. Substances like vinegar and some soft drinks are acids too. The scene changes to show a bottle of vinegar and a can of cola. TIM: Acids release positively-charged hydrogen atoms when they are dissolved in water. The scene changes to Moby squeezing a lemon into a pitcher that has some water in it. The lemon juice is yellow and can be seen floating in the water. TIM: When those hydrogen atoms combine with water molecules, hydronium ions form. An animation shows water molecules and hydrogen ions floating around on a gray background. The hydrogen ions are represented by a red dot surrounded by a dotted circle. Text reads: “hydrogen ion left-parenthesis Upper H plus right-parenthesis.” The water molecules are represented as three dotted circles, one larger and two smaller. The two smaller circles are of the same size. Each circle has a red dot in the middle. The largest of the three circles contains a fourth smaller circle. Along the edge of the larger circle, there are 8 blue dots. On the circle within the larger circle, there are 2 blue dots. Each of the smaller circles intersects the large one at two points. At each intersection, there is a blue dot. Text reads: “water molecule left-parenthesis Upper H 2 Upper O right-parenthesis.” The animation continues to show the hydrogen ion combining with the oxygen molecule to form a hydronium ion. The smaller circle that represents the hydrogen ion attaches to the largest circle of the water molecule. It intersects the circle at two points. At each intersection, there is a blue dot. Text reads: “hydronium ion left-parenthesis Upper H 3 Upper O plus right-parenthesis.” TIM: Acid solutions can conduct electricity since they contain these ions. The scene changes to a lemon and a digital clock. The clock is connected to the lemon with wires. TIM: Some acids can even eat away at metal! Tim is standing on the right, and a glass beaker on the left contains a clear acid liquid. A piece of metal is dropped into the beaker, and the liquid begins to bubble. (bubbling, sizzling sound) The piece of metal begins to shrink along the outside as the acid eats away at it. TIM: And those cool stalactites and stalagmites in caves are formed by carbonic acid dissolving the minerals in the rock. The scene changes to show a cave. From the roof of the cave, there are several rocky outcroppings that are cone-shaped. Water drips from the tips of these cones. Coming up from the ground of the cave are similar cone-shaped rock outcroppings. TIM: A sour taste is a property of acidic solutions, but you don't want to go around doing acid taste tests. 'Cause that's dangerous. Moby drinks from a metal cup. He then gets a puzzled look on his face and looks down into the cup as he brings it away from his mouth. TIM: The pH scale gives you a measure for identifying acids and bases. A diagram shows a p Upper H scale. Above the left side of the scale, text reads: acidic. Above the right side of the scale, text reads: basic left-parenthesis alkaline right-parenthesis. Fourteen vertical lines divide the scale into 15 equal sections. Each section is labeled from 0 to 14. The leftmost section is red. As you move right, the sections fade in color until the middle section at 7, which is white. The rightmost section is blue. Similarly, as you move left, the sections fade in color until the middle section. TIM: pH stands for “potential of hydrogen,” and the scale ranges from 0 to 14. A pH of 0 means “extremely acidic,” and a pH of 14 means “extremely basic.” A downward-facing arrow points to the left-most rectangle of the pH scale as Tim says “extremely acidic.” The arrow moves to the right along the pH scale to the right-most rectangle as Tim says “extremely basic.” The arrow changes from red to blue, reflecting the shades of color of the pH scale as it moves to the right. TIM: Anything with a pH of lower than 7 is acidic, and anything with a pH of higher than 7 is basic. The animation continues as the arrow moves back to the middle of the scale. The shade of the arrow continues to match the shade of the rectangles on the scale as it moves. The arrow moves left as Tim says “lower than 7.” The arrow moves right as Tim says “higher than 7.” TIM: A substance with a pH of exactly 7, like distilled water, is called pH neutral. The scene changes to Tim holding a glass of distilled water. MOBY: Beep? Beep? TIM: Right. I'm getting to the bases. Bases also contain hydrogen, but they form hydroxide ions when they dissolve in water. The scene changes to show water molecules and hydroxide ions floating around a gray background. The water molecules are represented as three dotted circles, one larger and two smaller. The two smaller circles are of the same size. Each circle has a red dot in the middle. The largest of the three circles contains a fourth smaller circle. Along the edge of the larger circle, there are 8 blue dots. On the circle within the larger circle, there are 2 blue dots. Each of the smaller circles intersects the large one at two points. At each intersection, there is a blue dot. The hydroxide ions are represented as two circles, one larger than the other. Each circle has a red dot in the middle. The larger of the two circles contains a third, smaller circle. Along the edge of the larger circle, there are 8 blue dots. On the circle within the larger circle, there are 2 blue dots. The smaller circle that is outside the larger one intersects the larger one at two points. At each intersection, there is a blue dot. Text reads: “hydroxide ions left-parenthesis Upper O Upper H minus right-parenthesis.” TIM: Since bases contain ions, they can conduct electricity, just like acids. The animation continues to show the hydroxide ion floating off the bottom of the screen. TIM: Chalk is a base, and so is soap and other cleaning products. The scene changes to show a green chalkboard. Words are written on it in chalk. Text reads “acids and bases are.” The animation continues to show a soapy sponge whipping across the chalkboard to erase some of the chalk. After the erasure, the part of the chalkboard that was cleaned is a deeper shade of green, and soapy bubbles begin to drip downward. TIM: Basic solutions feel slippery and taste bitter. But again, you'll have to take our word for that, because it's never a good idea to go around tasting stuff, especially in a science lab. The scene changes to show Tim and Moby. Moby holds up a sign with text that reads: “Safety First.” TIM: Hydroxide ions don’t react with metal, so a base won’t damage your pots and pans like an acid could. Moby is washing dishes. He is facing the sink, and his back is to the screen. To his left is a dish drying rack. To his right are some pots and pans and a stack of plates. TIM: Hey, thanks for doing those dishes, but you might want to slow down a bit. Moby begins going faster and faster as steam builds up in front of him and water splashes out of the sink. (splash) TIM: Hah! You didn't get me that time. Safety goggles! The scene changes to Tim. He is wearing goggles and is covered in soapy water. A plate then flies across the screen as Tim ducks so he is not hit with it. (plate breaking) Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts